Luminescent Solar Concentrators (LSCs) are large-area sunlight collectors. Efficient LSCs can significantly reduce the cost of expensive PV technologies (such as III-V PVs). Because of their semitransparent appearance, they can also enable novel-concept PV technologies such as solar windows that can turn currently energy-consuming buildings into power-generation units.

The efficiency of these solar windows, however, has been plagued by the imperfect photoluminescence (PL) efficiency of the luminophores used in LSCs and, in particular, the self-absorption loss of PLs photons of the luminophores.

 Quantum cutting process in Yb-doped nanocrystals doubles their emission quantum yields and completely suppressess self-absorption loss, thereby strongly ehancing the efficiency of luminescent solar concentrators.

Recently, researchers at the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences found an approach called quantum cutting to address these issues for solar windows.

Using ytterbium doped perovskite nanocrystals, researchers showed that absorption of one blue photon by the nanocrystal host led to the emission of two near-infrared photons from the ytterbium dopants. This is a signature of quantum cutting, i.e., cutting one photon into two while conserving the total energy.

By incorporating these doped nanocrystals into polymer matrix, they fabricated the first quantum cutting LSC with the highest ever internal optical efficiency, two-fold higher than previous records.

This quantum cutting approach should provide a bright future for solar windows.

The above work entitled "Quantum-Cutting Luminescent Solar Concentrators Using Ytterbium-Doped Perovskite Nanocrystals" was publised in Nano Letters. (Text by LUO Xiao)